Reland: DirectRenderer allows empty swap rects for CommitOverlayPlanes

Previously DirectRenderer would expand the damage rect to the full
output when partial swap buffers was not supported, because it had to
swap the whole buffer. Now, with the availability of CommitOverlayPlanes
it's possible that the surface has capability "allow_empty_swap", which
means swapping an empty rect is valid regardless of whether partial
swap is available. The surface is responsible for translating an empty
swap rect into a call to CommitOverlayPlanes.

BUG=533630
CQ_INCLUDE_TRYBOTS=tryserver.blink:linux_blink_rel

Review URL: https://codereview.chromium.org/1489153002

Cr-Commit-Position: refs/heads/master@{#363106}

• cc/output/direct_renderer.cc[diff]
• cc/output/gl_renderer.cc[diff]
• cc/output/overlay_unittest.cc[diff]
• cc/output/renderer.cc[diff]
• cc/output/renderer.h[diff]
• cc/test/test_web_graphics_context_3d.h[diff]
• content/browser/renderer_host/compositor_impl_android.cc[diff]